Drilling



Dec. 3, 1968 BAUER ET AL DRILLING Filed March 28, 1957 7 Sheets-Sheet 1INVENTOR'S'. ROBERT E BAUER HAL STRATTON AARON D. RHODES V. AIZORNEYSDec. 3, 1968 v BAUER ET AL 3,414,067

DRILLING Filed March 28, 1957 7 Sheets-Sheet 2 INVENTORS ROBERT E BAUERHAL .STRATTON BY AARON D. RHODES ATTORNEYS FIG. 2.

DRILLING 7 Sheets-Sheet 5 Filed March 28, 1957 Dec. 3, 1968 R. F. BAUERET AL 3,414,067

DRILLING Filed March 28, 1957 7 Sheets-Sheet 1 r0 VESSEL INVENTOR-Sf 45ROBERT F BAUER HAL STRATTON BY AARON 0. R/-/00Es A TTORNEYS Dec. 3, 1968BAUER ET AL 3,414,067

DRILLING v 7 Filed March 28, 1957 7 Sheets-Sheet 5 INVENTORS ROBERT/TBAUER HAL STRATTON BY AARON D. RHODES Dec. 3, 1968 BAUER ET AL DRILLING7 Sheets-Sheet 6 Filed March 28. 1957 FIG 6.

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United States Patent 3,414,067 DRILLING Robert F. Bauer, Whittier, HalStratton, Pasadena, and

Aaron D. Rhodes, Arcadia, Calif, assiguors, by direct and mesneassignments, to Shell Oil Company, Los

Angeles, Calif., a corporation of Delaware Filed Mar. 28, 1957, Ser. No.649,137 21 Claims. (CI. 175-7) This invention relates to apparatus fordrilling and working on underwater wells.

The apparatus of the invention may be used in connection with wellsunder any kind of water, whether marine or fresh, but for simplificationof explanation of the invention, the apparatus is described as beingused in an ocean.

At the present time, there is considerable activity in exploring anddrilling for oil and gas at offshore locations. Currently, most of thedrilling is done from stationary structures rigidly anchored to theunderwater formation. These structures provide static bases for thedrilling equipment and are satisfactory for relatively shallow water.However, for deeper water, say depths of several hundred feet,stationary structures are not always economically practical.Furthermore, the stationary structures are permanent installations whichmay be navigation hazards.

Recently there has been developed, as described in copending applicationSer. No. 468,214, filed Nov. 12, 1954, now Patent No. 2,808,229,apparatus and method for drilling underwater wells from a floatingvessel. Drilling from a floating vessel has the advantage over drillingfrom a stationary structure that the floating vessel may be readilymoved from one location to another, is less expensive to set up, and maybe quickly removed in the event of a storm.

One of the difiiculties in drilling or working on an underwater wellfrom a floating vessel is in guiding drilling and other equipment such.as tubing, casing, etc., to the well from the surface of the water. Themovement of a floating vessel due to wind, current and wave action,which is almost invariably present, makes it difficult to relocate thewell once equipment is moved from it.

This invention provides drilling apparatus in which equipment mayreadily be guided from a floating vessel to and from an underwater well.

Briefly, the invention contemplates apparatus for drilling a hole in aformation underlying a body of water. The apparatus includes a floatingvessel and means for anchoring the vessel over the hole or well site. Awell head base adapted to be secured firmly to the formation is anchoredat the well site. The base includes a receiver which overlies the upperend of the hole. An elongated conductor is adapted to fit around .adrill string which is adapted to extend from the vessel into the hole.The conductor is adapted at its lower end to seal to the receiver, andextend from the receiver to the floating vessel to provide a closedpassageway around the drill string from the receiver to the vessel.Means are provided for lowering and guiding the conductor so that as itis lowered, the lower end of the conductor fits into sealingrelationship with the receiver and registers with the upper end of thehole.

In the preferred form, the elongated conductor is provided with buoyantsupport to maintain it in a substantially upright position, and inrelatively shallow water the conductor also preferably includes asection of flexible hose in its lower portion to accommodate lateraldisplacement of the conductor. Also in the preferred form, the conductoris adapted to make a quick seal to and release from the receiver bymeans which are controlled remotely from the floating vessel, so thatthe conductor may be either quickly sealed to or released from thereceiver by remote control.

Also in the preferred embodiment, the receiver includes a blow-outpreventer which can be controlled from the surface of the water to closethe upper end of thewell. Thus, the well can be safely shut in whiledrilling operations are temporarily suspended, the top of the conductorthen lowered a substantial distance below the water surface and nostructure is left at or near the surface of the water which would eitherbe damaged by storm or present a navigation hazard.

These and other aspects of the invention will be more fully understoodfrom the following detailed description taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a schematic elevation of a well head base and receiver beinglowered from a floating vessel into a hole which is being drilled in anunderwater formation;

FIG. 2 is an enlarged elevational view of the well head base in itsfinal position on the ocean floor;

FIG. 3 is a fragmentary plan view of the well head base taken on line 33of FIG. 2;

FIG. 4 is a schematic and fragmentary elevation of the elongatedconductor supported by buoyant chambers spaced along its length, theconductor extending from the receiver to the floating vessel;

FIG. 5 is an enlarged schematic and fragmentary elevation, partly insection, showing the sealing mechanism at the lower end of theconductor, the flexible section in the lower portion of the conductor,and the detail of how one of the buoyant chambers is secured to theconductor;

FIG. 6 is a view taken on line 66 of FIG. 5; and

FIG. 7 is a fragmentary schematic elevation, partly in section, showingthe presently preferred embodiment of the invention, in which the upperend of the conductor is secured to the floating vessel and provided witha slip joint to permit vertical displacement of the vessel with respectto the lower portion of the conductor.

Referring to the drawings, FIG. 1 shows a well head base 18 supported bysupport or guide lines 19, and being lowered by the support or guidelines in a body of water 20 from a floating drilling barge 21 toward awell 22 being drilled from the barge in an underwater formation 23. Theupper ends of the support or guide lines may be controlled by suitablemeans, such as winches (not shown). Once the well head base is anchored,as described below, the winches, which are powered through torqueconverter transmissions (not shown) are used to maintain constanttension in the support or guide lines to preclude their fouling and toaid in guiding equipment down them, as is also described below. Thebarge is anchored over the well by a plurality of suitable anchor lines24 extending in opposite directions from the barge and connected toanchors (not shown).

A draw works 25 and a power unit 26, which may be of conventional type,are mounted on the barge to operate the hoisting cable 27 carried over acrown block 28 located at the upper end of a derrick 29. The travellingend of the hoisting cable carries a travelling block 30 and a hook 31which supports a swivel joint 32. A kelly joint 33 extends downwardlyfrom the swivel through a kelly bushing 34 in the center of a rotarytable 36 mounted on gimbals (not shown) in a manner similar to thatdescribed in US. Patent 2,606,003. The rotary table is supported on aplatform 37 directly over a cellar 38 which may be located in the centerof the barge as illustrated. Power is supplied to the rotary tablethrough a shaft 39 turned by a rotary table power unit 40.

A string of drill pipe 41 is connected to the lower end of the kelly andextends down through the cellar, a central opening 42 in the well headbase (see FIG. 3), the water and into the well. A drill collar 43 and anunderreamer drill bit 44 are attached to the lower end-of the drill pipefor boring the well to a diameter slightly larger than the outsidediameter of a casing or anchor 45 which is welded at its upper end tothe well head base in the central opening of the well head base, andwhich projects downwardly from the well head base. One or more blowoutpreventers 45A are attached to the upper end of the casing 45 and extendabove the top of the well head base. A mandrel or receiver 458 in theform of relatively short section of pipe approximately the same diameteras the casing, is attached at its lower end to the blow-out preventers.The blow-out preventers are of conventional type so that the well may beclosed off with drill pipe in it or out of it. The blow-out preventersare actuated through a control line 45C which extends from the blowoutpreventers to the floating vessel.

During the stage of the drilling operation shown in FIG. 1, drillingfluid or seawater is pumped down the drill pipe to wash cuttings out ofthe Well as drilling proceeds, no attempt being made at this time toobtain return circulation.

As shown in FIG. 2, once the well is drilled to a sufficient depth toreceive the casing, the well head base is lowered from the barge bymeans of guide lines so that the casing slides down around the drillpipe and into the well, the bottom of the well head base resting on theearth formation around the upper end of the well. During this operation,the blow-out preventers are held open so that the casing slides freelydown the drill pipe. Preferably, the conductor pipe is of sufticientlength to be firmly anchored in the formation by cementing it in placeby well known techniques. The under-reamer may be retracted and thedrill pipe, drill collar and drill bit removed from the well bore, ordrilling may be continued without removing the drill bit from the welluntil some later period of the drilling operation.

As shown most clearly in FIGS. 2 and 3, the well head base is arelatively flat and wide structure which is hexagonal in shape, asviewed in plan. The periphery of the bottom of the well head base ismade up of six sections 46 of I-beams of equal length welded togetherend to end to form a hexagon. A separate vertical brace 47 is welded tothe junctions of the ends of each of the I- beam sections 46 andconnects the bottom of the well head base to the top of the well headbase, which is also for-med of six sections 48 of I-beams weldedtogether end to end to form a hexagon identical in size and shape to thebottom of the well head base.

An upper set of horizontal and radially extending braces 50 extendedfrom the junctions of the ends of the peripheral sections of the top ofthe well head base to terminate at the outside diameter of the upper endof the casing, to which they are welded. A lower set of horizontalradially extending braces 51 are similarly welded to the junctions ofthe ends of the peripheral sections of the bottom of the well head baseand are welded at their inner ends to the casing in the plane of thebottom of the well head base. A set of six diagonal braces 52 extendingupwardly and inwardly from the junctions of the ends of the peripheralsections of the bottom of the well head base are welded at their lowerends to the base bottom and at their upper ends to the casing.

A plurality of separate water tight compartments 53 are attached to theinterior of the well head base so that it may be floated and towed toany desired location. A pad-eye 54 welded to one of the radial sectionsin the top of the well head base provides a convenient means forattaching a tow line (not shown).

An annular circular plate 55, is disposed around the central opening 42in the well head base. The plate 55 is welded to the top surfaces of theradially extending braces in the top of the well head base. Three cones57 spaced at 120 intervals on a common circumference are welded to thetop surface of the circular plate. A separate pad-eye 58 is welded tothe upper end of each cone, and the lower end of a separate guide line19 is connected to each pad-eye with a swivel 9 a d a Shackle A drillingoperation as illustrated in FIG. 1 is commenced with the well head baseas follows: 7 The Well head base is towed to the desired location, andthe drilling barge is firmly anchored over the well site. The guidelines are connected to the well head base cones, and the tow line isdisconnected from the well head base. The buoyant compartments in thewell head base are then flooded either by puncturing the wall of thecompartments or by opening valves (not shown).

The upper ends of the guide lines being controlled from the drillingbarge, the well head base compartments are flooded until the base has aslight negative buoyancy. Suitable handling lines (not shown) are thenattached to the base and it is then pulled to the position shown in FIG.1, i.e., under the cellar in the barge, where it is held by the guidelines at a shallow depth below the cellar. The drill bit, drill collarand drill pipe are then made up on the barge and lowered through thereceiver, blow-out preventers, which are open, and the casing. Thedrilling operation then proceeds as described above until a suflicientdepth is reached to permit the casing to be lowered into the well andallow the bottom of the well head base to rest on the ocean floor.Preferably the casing is then cemented in place.

For operation in areas where the water depth is less than the overalllength of the desired amount of casing and the well head base, the baseis anchored by a slightly different procedure. The base is maneuveredinto the position shown in FIG. 1 without the casing, blow-outpreventers and receiver. A joint of casing is inserted to the opening ofthe base and supported by suitable means from the barge so that thelower end of the casing is flush with the bottom of the base. The baseand casing are then lowered simultaneously, successive joints of casingbeing added, until the base is resting on the bottom, and the upper endof the casing extends up into the barge above the water level. Usingsalt water without return circulation, sufficient hole is drilled withthe bit and underrea-mer to receive the desired amount of easing. Saltwater is then displaced with mud to keep the hole open, and the top ofthe casing is lowered a few feet into the upper end of the hole. Thedrill pipe and bit are withdrawn, and the remainder of the casing isthen run down into the hole. The blow-out preventers and receiver areflanged to the upper end of the casing, which is then lowered so thatthe blow-out preventers rest on the top of the well head base. The drillpipe is also lowered within the upper end of the casing so that isextends down below the blow-out preventers. When the casing reaches itslowermost position, the blow-out preventers are closed on the drill pipeand the casing cemented in place by pumping cement down through thedrill pipe and forcing cement into the annular space between the casingand the hole. The drill pipe is then removed and the cement is allowedto set.

At this point it is necessary to have apparatus which will permitequipment to be guided accurately to the Well bore. Such apparatus isshown in FIGS. 2 through 6.

Referring to FIGS. 4 and 5, a guide assembly 64 is adapted to slide upand down the guide lines and carry with it a guide bracket 65 adapted toslide up and down with respect to the guide assembly. The guide assemblyincludes a horizontal circular hoop brace 66 at its lower end which ismade up of three equal segments welded at each end to the lower ends ofthree hollow vertical guide posts 67. A respective guide line passesthrough each guide post. The upper end of each guide post is threadedand a separate guide post cap 68 having an outside diameter slightlygreater than the diameter of the guide post is screwed on to the upperend of each guide post. Each guide post cap has a central opening 69 toaccommodate a respective guide line. A separate hollow guide assemblycone 70 is welded to the lower end of each guide post and adapted tonest on a respective well head base cone so that the guide assembly iscentered above the central opening in the well head base when the guideassembly is lowered to rest on it, and so that forces and loads of theguide assembly are transferred to the well head base.

The guide bracket includes three vertical sleeves 71, each sleeve havingan inside diameter to make a sliding rit over a respective guide post.The outside diameter of each sleeve is substantially the same as theoutside diameter of each guide post cap, which limits the upward travelof the equipment bracket on the guide assembly. A separate, horizontalupper arm 72 is welded at its outer end to each guide post and extendsradially and inwardly for a relatively short distance toward the centerof the guide assembly. A separate horizontal lower arm 73 is similarlyattached to each guide sleeve below a respective upper arm.

The inner end of each guide bracket arm is welded to the exterior of aconductor seal housing $0, which has an upright central bore 82 throughit adapted to fit over the upper end of the receiver. A short, verticaltubular coupling 84 is welded around the upper end of bore 82, which isof substantially the same diameter as the internal bore of the receiver.The lower end of a strong heavy-wall, flexible section of rubber hose 86is connected by a clamp 88 to the coupling, and the upper end of therubber hose is connected by clamp 90 to the lower end of an elongatedconductor 92 which is made up of a plurality of pipe sections 93threaded at each end and held together by external collars 94 which formexternal shoulders 95 (see FIG. 5) on the conductor. The rubber hosesection may be omitted if the length of the conductor is suflicient toprovide the necessary flexibility to accommodate the random motion ofthe barge. A separate annular buoyant chamber 96 is disposed around theconductor under each collar. With this arrangement the conductor is freeto flex laterally within its elastic limit and not be constrained by thebuoyant chambers.

As shown in FIG. 4, one end of a conductor supporting cable 98 isattached to a lug 99 welded to the upper end of the conductor. The otherend of the conductor cable extends upwardly from lug 99 past a roller100 to a winch (not shown) on the drilling barge. The winch is poweredby a torque converter transmission so the supporting cable is held underconstant tension to support the conductor, and yet leave the floatingvessel free to move vertically with respect to the conductor. One ormore additional conductor cables and winches may 'be providedsymmetrically around the upper end of the conductor to provide abalanced support for it. The upper end of the conductor has a lateralconduit 108 through which drilling mud returns to a mud pit 84. Anannular guard ring 109 is attached to the barge cellar walls and makes aclose sliding fit around the conductor below lug 9'9 and permitsrelative vertical movement between the barge and conductor, while at thesame time limiting relative lateral movement between the barge andconductor.

The lower end of the conductor is adapted to be releasably sealed to thereceiver by means of a heavy-wall rubber sleeve 110 (see FIG. 5) mountedwithin the conductor seal housing. Starting at the top of the housing,the central bore 82 is of substantially the same diameter as theinternal diameter of the receiver. The bore is then stepped to anincreased diameter to form an upper section 112 and then increased againto form a central section 114. The upper end of the seal sleeve 110 ismolded into an annular groove 116 formed in the shoulder between bores112 and 114. Below central section 114 of the central bore in the sealhousing, the bore is stepped down to form a section 118 of the samediameter as section 112. The lower end of the seal sleeve is molded intoan annular groove 120 in the shoulder formed between sections 114 and118. The lower end of the bore has a section 122 which tapers downwardlyand outwardly to match a similar surface on the upper end of theblow-out preventer. A conduit seal control line 124 extends down fromthe floating vessel and is adapted to supply fluid pressure to anannular spacing 125 formed between the seal sleeve and the seal housing.With the seal housing disposed over the receiver as shown in FIG. 5,fluid pressure applied by line 124 forces the sleeve to extend inwardlyand seal around the receiver, providing a closed path for the flow ofdrilling fluid back to the floating vessel.

The installation and use of the conductor is as follows:

Once it is determined that return circulation is necessary, or thatequipment must be removed from and returned to the well, the guide lines19 are threaded through the hollow guide posts of the guide assembly onthe barge. The upper end of each respective guide line is then disposedover a separate winch (not shown) powered by a torque convertertransmission, and held taut. The conductor seal housing, the section ofrubber hose, and the first section of casing, all of which arepreviously made up on the barge, are then held suspended in the cellarof the floating vessel. The first buoyant chamber, which is to be thelowest chamber once the conductor is sealed in the position shown inFIG. 4, is slipped on to the upper end of the section of conductor pipeconnecte to the rubber base. A collar and the next section of conductorpipe are then coupled to the upper end of the section of conductor pipe.This process is repeated, making the conductor up to the required lengthand lowering it as sections of the conductor pipe collars and buoyantchambers are added. This procedure continues until the conductor pipe isof the length shown in FIG. 4. At this time, the guide assembly conesnest over the well base cones and center the conductor seal housing overthe upper end of the receiver. The conductor is then lowered a shortdistance, permitting the sleeve 71 to slide down the guide post so thatthe seal housing comes to rest in the position shown in FIGS. 4 and 5.Fluid pressure is then supplied to the seal housing through line 124 toseal the conductor pipe to the receiver.

The placing of the conductor in the position shown in FIGS. 4 and 5 asdescribed above, may be achieved with the drill pipe either in or out ofthe well, the drill pipe being disconnected from the kelly and theconductor being stripped down over it in the event the drill pipe isleft in the well.

With the apparatus in the position shown in FIGS. 4 and 5, drillingproceeds in a routine fashion, additional casing 139 and blow-outpreventers (not shown) being guided through the conductor pipe, and setas drilling proceeds to greater depths.

The advantage of the apparatus of this invention is that repeated tripsin and out of the well with drilling or other equipment may be madethrough the conductor pipe, so that the flexible guide means arenecessary primarily only for the relatively infrequent occasion forsealing the lower end of the conductor to the receiver.

The well site may be temporarily abandoned by several differentprocedures, the particular procedure depending on the conditions.

If it is desirable to leave the well site in the shortest possible time,say, due to a sudden storm, and drilling is in progress, severalsections of drill pipe are quickly removed and the upper end of thedrill pipe is plugged. The drill pipe is then lowered until the drillbit is almost on bottom and the blow-out preventers are closed aroundit. The blow-out preventer control line is sealed under pressure, buoyedand cast ofl. The upper portion of the conductor is removed below thewater surface, and stored on the floating vessel, as is the conductorsupporting cable. The guide lines and control line 124 are buoyed andcast off from the floating vessel. The barge is then moved away from theconductor. The buoys mark the well site for the return of the barge whendrilling is to be resumed.

Ordinarily, suflicient advance notice is available to allow time toleave the well site so that all or most of the drill pipe can beretracted and so that the conductor can be released from the receiverand withdrawn to the floating vessel. Under these conditions, theblow-out preventers are left closed and the control lines, along withthe guide lines, are left buoyed as before.

FIG. 7 shows the presently preferred embodiment of the invention inwhich the apparatus is adapted to be abandoned temporarily and in arelatively short period of time, such as might be required due to thesudden occurrence of a storm. The conductor 92 is secured by theconductor seal housing 80 to the well head receiver 45B as describedwith respect to FIG. 5. The upper end of the conductor terminates in aslip joint 139 located a substantial distance below the surface of thewater to provide safe navigational clearance for the drilling barge andother vessels which might be in the area, and to be below anysubstantial wave effects. An annular buoyant chamber 140 is connected tothe upper end of the conductor below the slip joint 139 and providessuflicient buoyancy to support the conductor in the upright positionshown. The control lines 45C and 124 for the blowout preventers andconduit seal housing, respectively, are secured by a clamp 141 to thechamber and extend on to the barge.

An annular extension conduit seal housing 142 is secured to the uppersurface of the buoyant chamber around the central opening in thechamber. The lower end of an upright extension conduit 144 extends downinto the conduit seal housing and the opening in the buoyant chamber.The conduit seal housing is adapted to be sealed firmly to the extensionconduit by an internal rubber sleeve 146 which is secured at each end tothe housing and actuated by fluid pressure applied through a line 148extending to the drilling barge. A horizontal stop piston 150 isdisposed in a cylinder 151 on the upper end of the conduit seal housing,and is urged inwardly by a compression spring 152 against the extensionconduit sothe piston will engage an annular groove 154 near the lowerend of the extension conduit when the conduit is raised, and therebyprevent the conduit from being pulled inadvertently up out of theconduit seal housing. Fluid pressure may be applied through a line 156to hold the locking piston outwardly against the spring to permit thewithdrawal of the extension conduit when desired.

A slidable tube 158 is disposed in, and projects upwardly from, theupper end of the extension conduit. A packing gland 160 in the upper endof the extension conduit may be adjusted by bolts 162 to provide thedesired sealing between the tube and the extension conduit, i.e., thegland is adjusted to permit the tube to slide freely with the verticalmotion of the drilling barge, and yet be tight enough to prevent leakageof drilling mud. An external gutter 164 is on the extension conduitunder the packing gland to catch any drilling mud which might leakthrough the gland. A suitable sump pump (not shown) has its intakedisposed in the sump to carry away any drilling mud which might becollected in the gutter.

The upper end of the sliding conduit is supported by a cable 166 whichis secured by suitable means to the barge. The drill pipe extendscoaxially down through the tube, the extension conduit, the conductor,and into the well, as described previously with respect to FIG. 5.

A mud return nipple 168 on the upper end of the tube is connected byflanges 170 to a mud return hose 172 which discharges on to a shaker andscreens 174, which are disposed above a collector 176 which returns mudto the mud pit.

The operation of the apparatus shown in FIG. 7 is relatively simple.With the well head base located as shown and described with respect toFIG. 5, the conductor and conductor seal housing are lowered down theguidelines and sealed to the receiver conduit as shown in FIG. 7, theupper end of the sliding tube being retained on the drilling barge.Fluid pressure is applied to the extension conduit seal so that theextension conduit is firmly held with respect to the buoyant chamber.Drill pipe is then lowered down the tube and into the well, and drillingoperations are conducted in a substantially conventional fashion, i.e.,drilling mud is circulated down the drill pipe as the pipe is rotated,and the mud returns back up the annular space between the drill pipe,the conductor, and the tube. The crnud flows out of the mud returnnipple, through the mud return hose and on to the shaker screens. As thedrilling barge is moved up and down by wave action, the sliding tube andshakers and screens move with it so that there is always a constantelevation between the mud return nipple and the shaker screens toprovide for the steady and uninterrupted return of the drilling mud. Thepacking gland between the tube and the extension conduit permits tnetube to slide and yet maintain a fluid tight seal with the extensionconduit. The packing gland and its adjustment are located above thewater level so that its operation can be easily observed and so that itcan readily be adjusted or repaired. At any time it may be desired, thefluid pressure applied to the extension conduit seal housing can bereleased to permit the extension conduit to be adjusted to any requiredheight, the locking piston 150 and the annular groove in the lowerportion of the extension conduit preventing the inadvertent removal ofthe extension conduit from its sealing housing.

If it becomes necessary to leave the well site quickly, the drill pipeis either completely removed from the hole, or else a suflicient lengthis removed from its upper end to permit it to be plugged and loweredback into the well so that its upper end is well below the surface ofthe water. The blow-out preventers are closed to shut in the well, andthe mud return nipple is disconnected from the mud return hose. Pressureis released from the extension conduit seal housing and the extensionconduit and tube are lowered from the drilling barge until the annulargutter on the extension conduit rests on the upper surface of theextension conduit seal housing, and the drilling mud return nipple restson the upper end of the extension conduit. Control lines 45C, 124, 148and 156 are sealed, disconnected from the barge, buoyed and cast olf.Supporting cable 166 and the guide lines are buoyed and cast off, so thebarge can then be moved from the loca- -tion.

When drilling is to be resumed, the barge is returned to and anchoredover the well site, being guided by the buoys. The control lines, guidelines and cable 166 are picked up and arranged on the drilling barge asdescribed previously. The slidable tube is then raise-d by cable 166. Anannular external lip 178 on the lower end of the tube engages aninternal annular lip 1 at the upper end of the extension conduit andraises the extension conduit to the desired position. Line 148 isre-connected to the source of fluid pressure on the barge, andpressurized to lock the extension conduit in the required position. Thetube is again supported by line 166 as shown in FIG. 7, and the drillpipe, if left in the well, is retrieved by a conventional fishingoperation, and drilling is then resumed as described above.

As can be appreciated from the foregoing description, the well can beabandoned in a relatively short time, and drilling operations can beresumed with a minimum amount of difficulty.

We claim:

1. Apparatus for carrying out operations such as drilling and working ina well in a formation underlying a body of Water comprising a floatingvessel disposed over the Well site, a rotary drilling rig including arotary table mounted on the vessel, an elongated hollow conductorextending between the vessel and the formation, the conductor being madeup of an upper section and a lower section, remotely controllablecoupling means near the bottom of the water body for sealing the twoconductor sections together, the upper end of the upper section beingspaced below the rotary table to have a free space between them and thelower end of the lower section of the conductor being disposed in thewell, means for raising and lowering the upper section of the conductor,means for finmly anchoring and sealing the lower end of the lowersection of the conductor to the formation, a blow-out preventer disposedin the conductor below the coupling means, a buoyant support attached tothe upper portion of the conductor, a slip joint in the conductor abovethe buoyant chamber, means for changing the effective length of theupper section of the conductor, means for attaching the conductor to thevessel above the slip joint, a drill pipe extending down through therotary table into the conductor, means for pumping drilling mud downthrough the drill pipe, a mud screen mounted on the vessel, a lateralconduit connected at one end to the upper portion of the conductor andhaving its other end disposed over the screen, an elongated laterallyflexible support member attached at its lower end to the lower sectionof the conductor, and terminating at its upper end at the vessel, andmeans interconnecting the upper section of the conductor and the supportmember so that as the lower end of the upper sec tion of conductor islowered, it is constrained by the support member to register with theupper end of the lower section of the conductor.

2. Apparatus for carrying out operations such as drilling and working ina well in a formation underlying a body of water comprising a floatingvessel, a generally upright elongated hollow conductor disposed beneaththe vessel so the upper end of the conductor terminates in the vicinityof the vessel, an anchor including an opening therethrough communicatingat one end with the upper end of the well, releasable coupling means forconnecting the lower end of the conductor to the anchor to form throughthe opening in the anchor a continuous conduit between the well and thevessel, means for moving equipment to and from the well through theconductor, remote control means for releasing the coupling means fromthe water surface to permit the conductor and anchor to be separatedfrom each other, and means for guiding the conductor from the floatingvessel to the anchor so the coupling means connects to the anchor toform the said continuous conduit.

3. Apparatus for carrying out operations such as drilling and working ina well in a formation underlying a body of water comprising a floatingvessel disposed over the well site, an elongated casing disposed beneaththe vessel, an elongated laterally flexible support member attached atone end to the casing and terminating at its other end at the floatingvessel, means for lowering the casing from the vessel toward theformation with the support member, means for guiding the casing to theformation so the casing enters the well, means forming an elongatedenclosed passage between the vessel and the well and collinear with thecasing, means for firmly anchoring and sealing the lower portion of thepassage forming means to the formation, and means for moving equipmentbetween the vessel and well through the passage.

4. Apparatus for carrying out operations such as drilling and working ina well in a formation underlying a body of water comprising a floatingvessel, a generally upright elongated hollow conductor disposed beneaththe vessel so that the upper end of the conductor terminates in thevicinity of the vessel, an anchor including an opening therethroughcommunicating at one end with the upper end of the well, releasablecoupling means for connecting the lower end of the conductor to theanchor to [form through the opening in the anchor a continuous conduitbetween the well and the vessel, means for moving equipment to and fromthe well through the conductor, means for releasing the coupling meansfrom the water surface to permit the conductor :and anchor to beseparated from each other, and means for guiding the conductor from thefloating vessel to the anchor so the coupling means connects to theanchor to form said continuous conduit.

5. Apparatus, for carrying out operations such as drilling and workingin a well in a formation underlying a body of water, comprising afloating vessel disposed over a well site, an elongated hollow conductordisposed beneath the floating vessel so that the upper end of theconductor is connectable to the vessel, means sealing the lower end ofthe conductor to the well, a slip joint in the conductor below the watersurface, said slip joint being of such a length so as to permit thelowering of the upper end of the conductor from an operating position toa position substantially below the surface of the water, and a buoyantsupport attached to the conductor below the slip joint, said buoyantsupport having sufficient buoyancy to support the portion of theconductor disposed below the slip joint in a substantially verticalposition.

6. Apparatus, for carrying out operations such as drilling and workingin a well in a formation underlying a body of water, comprising afloating vessel disposed over the well site, an elongated hollowconductor disposed beneath the floating vessel with the upper end of theconductor terminating in the vicinity of the vessel, means sealing thelower end of the conductor to the well, a slip joint in the conductorbelow the water surface, said slip joint being of such a length as topermit the lowering of the upper end of the conductor from an operatingposition to a position substantially below the surface of the water, abuoyant support attached to the conductor below the slip joint, saidbuoyant support having sufficient buoyancy to support the portion of theconductor disposed below the slip joint in a substantially verticalposition, and a blow out preventer in the conductor below the buoyantsupport.

7. Apparatus, for carrying out operations such as drilling and workingin a well in a formation underlying a body of water, comprising afloating vessel disposed over the well site, an elongated hollowconductor disposed beneath the floating vessel, the conductor includinga lower section and an upper section, the lower section being beneaththe water surface and the upper section being slidable within the upperportion of the lower section and having its upper end terminating in thevicinity of the vessel, whereby .the upper section may be slidablylowered within the lower section so that the upper end of the uppersection is lowered from an operating position to a positionsubstantially below the surface of the water, means sealing the lowerend of the lower section of the conductor to the well, a buoyantsupport, and means attaching the buoyant support to the upper portion ofthe lower section of the conductor so as to maintain the lower sectionof the conductor in a substantially vertical position.

8. Apparatus, for carrying out operations such as drilling and workingin a well in a formation underlying a body of water, comprising afloating vessel disposed over the well site, buoyant support meanswithin the water and below the bottom of the vessel, an elongated hollowconductor disposed beneath the floating vessel, said conductor includinga lower section and an extension section, the extension section beingslidable within the lower section and having its upper end terminatingin the vicinity of the vessel, means sealing the lower end of the lowersection of the conductor to the well, means connecting the upper end ofthe lower section of the conductor to the buoyant support means so as tomaintain the lower section in a substantially vertical position, andmeans for selectively locking the extension section in various positionsagainst its longitudinal movement within the lower section so that theoverall length. of the conductor is selectively variable between amaximum length when the conductor is in its operating position and aminimum length when the upper end of the extension section is asubstantial distance below the surface of the water.

9. Apparatus in accordance with claim 8 further including means forremotely operating the locking means.

10. Apparatus, for carrying out operations such as drilling and workingin a Well in a formation underlying a body of water, comprising afloating vessel disposed over the well site, a drilling mud shakerscreen on the vessel, an elongated hollow conductor disposed beneath thefloating 'vessel, said conductor including a lower section and anextension section, the extension section being slidable within the lowersection and having its upper end terminating in the vicinity of thevessel, means sealing the lower end of the lower section to the well,buoyant support means, means connecting the lower section to v thebuoyant support means so as to maintain the lower section in asubstantially vertical position, means for selectively locking theextension section in various longitudinal positions within the lowersection so as to selectively vary the overall length of the conductorbetween a retracted length in which the upper end of the extensionsection is a substantial distance below the surface of: the water and anoperating length, a tubular section slidably fitted Within the upper endof the extension section, and a lateral mud line having one end attachedto the upper portion of the tubular section and its other end open ingover the shaker screen.

11. Apparatus, for carrying out operations such as drilling and workingin a well in a formation underlying a body of water from a vesselfloating on the water, comprising an elongated hollow conductorextending upwardly from the formation, a slip joint in the conductorwhich divides the conductor into an upper portion and a lower portion,said slip joint being positioned along the conductor so as to permit thelowering of the upper end of the upper conductor portion from anoperating position to a position a substantial distance below thesurface of the water, means sealing the lower end of the lower conductorportion to the formation, buoyant support means, and means forconnecting buoyant support means to the upper end of the lower conductorportion so as to maintain the lower conductor portion in a substantiallyvertical position.

12. Apparatus for carrying out operations such as drilling and workingin a well in a formation underlying a body of water comprising afloating vessel, a generally upright elongated hollow conductor disposedbeneath the vessel so the upper end of the conductor terminates at thevessel, an anchor including an opening therethrough communicating at oneend with the upper end of v the well, means for moving the conductordown and up to bring the conductor lower end into and out of a couplingposition with the anchor, remotely actuatable coupling means forconnecting the lower end of the conductor, when in the couplingposition, to the anchor to form through the opening in the anchor acontinuous conduit between the well and the vessel, an elongated guidemember, means connecting the guide member lower end to the formationadjacent the well, said guide member extending upwardly to the vessel,means engaging the conductor and guide member so that as the conductoris lowered it is constrained by the guide member to cause the conductorlower end, coupling means, and anchor to be in the coupling position,remote control means for actuating the coupling means from the watersurface to permit the conductor and anchor to be connected to andseparated from each other, and means for moving equipment to and fromthe well through the conductor when it is connected to the anchor.

13. Apparatus according to claim 12 which includes buoyant supportingmeans for the conductor.

14. Apparatus according to claim 12 which includes a plurality oflongitudinally spaced buoyancy chambers attached to the conductor.

15. Apparatus according to claim 12 in which conductor includes a slipjoint to permit one part of the conductor to move longitudinally withrespect to another part.

16. Apparatus for carrying out operations such as drilling and workingin a well in a formation underlying a body of water comprising afloating vessel, a generally upright elongated hollow conductor disposedbeneath the vessel so the upper end of the conductor terminates at thevessel, a casing disposed in the well, means for sealing the casing inthe well, blow-out preventer means connected in the casing, remotecontrol means for actuating the blow-out preventer means, means formoving the conductor down and up to bring the conductor lower end intoand out of a coupling position with the casing, remotely actuatablecoupling means connectable between the lower end of the conductor, whenin the coupling position, and to the casing so as to provide fluidcommunication therebetween, an elongated guide member, means connectingthe guide member lower end to the formation adjacent the well, saidguide member extending upwardly to the vessel, means engaging theconductor and guide member so that as the conductor is lowered it isconstrained by the guide member to cause the conductor, coupling means,and casing to be in the coupling position, remote control means foractuating the coupling means from the water surface to permit theconductor and casing to be connected to and separated from each other,and means for moving equipment to and from the well through theconductor when it is connected to the casing.

17. Apparatus for carrying out operations such as drilling and workingin a well in a formation underlying a body of Water comprising afloating vessel, a rotary drilling rig including a rotary table mountedon the vessel, a generally upright elongated hollow conductor disposedbeneath the vessel so the upper end of the conductor terminates at thevessel below the rotary table to leave a free space between the tableand the upper end of the conductor, an anchor including an openingtherethrough communicating at one end with the upper end of the well,means for moving the conductor down and up to bring the conductor lowerend into and out of a coupling position with the anchor, remotelyactuatable coupling means for connecting the lower end of the conductor,when in the coupling position, to the anchor to form through the openingin the anchor a continuous conduit between the well and the vessel, alaterally flexible elongated guide member, means connecting the guidemember lower end to the formation adjacent the well, said guide memberextending upwardly to the vessel, means engaging the conductor and guidemember so that as the conductor is lowered it is constrained by theguide member to cause the conductor, coupling means, and anchor to be inthe coupling position, remote control means for actuating the couplingmeans from the water surface to permit the conductor and anchor to beconnected to and separated from each other, and means for movingequipment to and from the well through the conductor when it isconnected to the anchor.

18. Apparatus for carrying out operations such as drilling and Workingin a well in a formation underlying a body of water comprising afloating vessel, 21 well head base having an opening through it, anelongated support member attached at one end to the base and terminatingat its other end at the floating vessel, means for lowering the wellhead base from the vessel toward the formation by the support member,means for positioning the base with respect to the formation so the baseopening is aligned with the well, an elongated conduit extendingdownwardly from the vessel, means for guiding the conduit through thebase opening and into the Well, means for firmly anchoring the lowerportion of the conduit to the formation, and means for moving equipmentbetween the vessel and well through the conduit.

1?. Apparatus for carrying out operations such as drilling and workingin a well in a formation underlying a body of water comprising afloating vessel, a well head base having an opening through it, anelongated laterally flexible support member attached at one end to thebase and terminating at its other end at the floating vessel, means forlowering the 'well head base from the vessel toward the formation by thesupporting member, means for positioning the base with respect to theformation so the base opening is aligned with the well, an elongatedconduit extending downwardly from the vessel, means for guiding theconduit through the base opening and into the well, means for firmlyanchoring the lower portion of the conduit to the formation, means formoving equipment between the vessel and well through the conduit, and abuoyant support connected to the conduit.

20. Apparatus for carrying out operations such as drilling and workingin a well in a formation underlying a body of water comprising afloating vessel, a well head base having an openingthrough it, anelongated laterally flexible support member attached at one end to thebase and terminating at its other end at the floating vessel, means forlowering the well head base from the vessel toward the formation by thesupport member, means for positioning the base with respect to theformation so the base opening is aligned with the well, an elongatedconduit extending downwardly from the vessel, means for guiding theconduit through the base opening and into the well, means for supportingthe conduit at the well head base, means for firmly anchoring the lowerportion of the conduit to the formation, and means for moving equipmentbetween the vessel and well through the conduit.

21. Apparatus for carrying out operations such as drilling and workingin a well in a formation underlying a body of water comprising afloating vessel, a generally upright elongated hollow conductor disposedbeneath the vessel so the upper end of the conductor terminates at thevessel, an anchor including an opening therethrough communicating at oneend with the upper end of the Well, means for moving the conductor downand up to bring the conductor lower end into and out of a couplingposition with the anchor, coupling means for connecting the lower end ofthe conductor, when in the coupling position, to the anchor to formthrough the opening in the anchor a continuous conduit between the welland the vessel, an elongated guide member, means connecting the guidemember lower end to the formation adjacent the well, said guide memberextending upwardly to the vessel, means engaging the conductor and guidemember so that as the conductor is lowered it is constrained by theguide member to cause the conductor, coupling means, and anchor to be inthe coupling position, and means for moving equipment to and from thewell through the conductor when it is connected to the anchor.

References Cited UNITED STATES PATENTS 2,628,818 2/1953 Graham -9339,630 4/1886 Douglas 166-46 X 2,248,015 7/1941 Armstrong 175-9 X2,676,787 4/1954 Johnson 175-7 2,684,575 7/1954 Pryor et al 175-8 X2,810,442 10/1957 Tausch 166-.5 X 2,836,247 5/1958 McCulloch 166-461,524,677 2/1925 Thompson 285-302 1,764,488 6/1930 Zublin 166-2411,766,628 6/1930 Grant 175-10 2,512,783 6/1950 Tucker 175-8 2,606,0038/1952 McNeill 175-7 2,610,028 9/1952 Smith 166-224 2,476,309 7/1949Lang 175-8 2,808,229 10/1957 Bauer et al 175-7 CHARLES E. OCONNELL,Primary Examiner.

R. E. FAVREAU, Assistant Examiner.

2. APPARATUS FOR CARRYING OUT OPERATIONS SUCH AS DRILLING A WORKING IN AWELL IN A FORMING UNDERLYING A BODY OF WATER COMPRISING A FLOATINGVESSEL, A GENERALLY UPRIGHT ELONGATED HOLLOW CONDUCTOR DISPOSED BENEATHTHE VESSEL SO THE UPPER END OF THE CONDUCTOR TERMINATES IN THE VICINITYOF THE VESSEL, AN ANCHOR INCLUDING AN OPENING THERETHROUGH COMMUNICATINGAT ONE END WITH THE UPPER END OF THE WELL, RELEASABLE COUPLING MEANS FORCONNECTING THE LOWER END OF THE CONDUCTOR TO THE ANCHOR TO FORM THROUGHTHE OPENING IN THE ANCHOR A CONTINUOUS CONDUIT BETWEEN THE WELL AND THEVESSEL, MEANS FOR MOVING EQUIPMENT TO AND FROM THE WELL THROUGH THECONDUCTOR, REMOTE CONTROL MEANS FOR RELEASING THE COUPLING MEANS FROMTHE WATER SURFACE TO PERMIT THE CONDUCTOR AND ANCHOR TO BE SEPARATEDFROM EACH OTHER, AND MEANS FOR GUIDING THE CONDUCTOR FROM THE FLOATINGVESSEL TO THE ANCHOR SO THE COUPLING MEANS CONNECTS TO THE ANCHOR TOFORM THE SAID CONTINUOUS CONDUIT.